Predictors of treatment failure after middle meningeal artery embolization for chronic subdural hematoma: a German nationwide multicenter study

Introduction Embolization of the middle meningeal artery (EMMA) is an emerging treatment for chronic subdural hematoma (cSDH), yet predictors of treatment failure (TF) remain incompletely characterized. We aimed to identify independent predictors of TF after EMMA for cSDH in a large German nationwide multicenter cohort. Methods In this secondary analysis of a retrospective multicenter study, 569 consecutive patients who underwent 718 EMMA procedures for cSDH across 30 German neurovascular centers (January 2014 to December 2023) were analyzed. TF was defined as residual cSDH >10 mm, hematoma progression, or requirement of rescue surgery. Rescue surgery alone, as well as absolute and relative size reduction, were secondary endpoints. The unit of analysis was the individual embolization procedure. Mixed-effects multivariable logistic regression was performed to identify independent predictors of TF. Results In multivariable analysis, cSDH thickness (adjusted OR (aOR) 1.09, 95% CI 1.05 to 1.13, P<0.001) and use of any antithrombotic medication (aOR 1.67, 95% CI 1.03 to 2.73, P=0.039) were independently associated with TF. Both predictors remained significant when analyses were restricted to first-time treatments and to hematomas of at least 10 mm. Only greater baseline cSDH thickness, but not antithrombotic medication, was associated with rescue surgery. Conclusion Antithrombotic medication use and greater hematoma thickness were independent predictors of TF after EMMA. These factors may guide individualized treatment selection.